Safety valve

ABSTRACT

A valve body defining a chamber with coaxial valve ports and valve seats on the ports facing the chamber. A valve member is movable axially in the chamber into engagement with either of the seats. The valve member is supported in the chamber, normally centrally between the seats, by a pair of coil springs which are seated in the valve ports and on opposite sides of the valve member. In some embodiments additional support of the valve member is provided by a rod extending axially through the valve member and having its end portions slidably journaled in bearing means provided in the valve ports. A fluid bypass from one port to the other is provided, either in the valve body or axially through the valve member.

PATENTED FEB 9 I97! 3.66.1; SHEU 1 UF 3 n m 4 I I 2 o h 2 I 4 6 4 B W I a 4 m 3 M 3 a M 5 l m a w 8 B- 4 5 2 Tu v V 4 a a a Q 3 B 8 3 3 2 Z G I F L nes.

v n 5 f INVENT OR Asa D. Sands BY M 524a ATTORNEY VALVE ACCESS BARREL FOR USE IN STREETS Valve access barrels for use in streets consist, as a rule of a frustoconical or cylindrical, hollow barrel body, which is provided with a bottom flange, open at the bottom and adapted to be closed by a cover at its top, and are incorporated in the street so that their top end face or the top face of the cover is aligned with the street surface and the barrel shields on all sides the top endportion of the actuating stem or the like of the valves incorporated in underground water mains so that a wrench can be applied to the end portion of the stem whenthe cover has been removed.

It is an object of the invention to provide a valve access barrel which ,is simple in structure, can be adjusted to different street levels without need for additional alterations and ensures a good fixation of the cover without need for special fixing parts.

The invention relates to a valve access barrel which comprises a hollow barrel body, which is frustoconical or cylindrical, provided with a bottom flange, open at the bottom and adapted to be closed at the top by a cover and to be increased in height by selectively usable, annular attachments, the barrel body, attachments and cover having conical seat faces which mate each other, the outside diameter of the attachments corresponding to the outside diameter of the barrel body at the top thereof and the largest outside diameter of the cover being smaller than said outside diameter of the barrel body at the top thereof. In such a valve access barrel, the above-mentioned object is accomplished in that the cover is adapted to fit directly into the barrel body and each attachment and carries a pilot extension, known per se, which extends into the barrel body and preferably cooperates with ribs of the barrel body. Because the cover need not be inserted into a separate connector but may be inserted into each attachment as well as into the barrel body itself, there is no need for the previous connector, which could be closed only by the cover. The basic structure now consists only of the barrel body and the cover. The selectively usable attachments may simply have an annular configuration. If the height of the valve access barrel is to be increased because the street level is to be changed, it is sufficient to remove the cover, apply the proper attachment and close the latter with the cover. There is no need to break away street covering material surrounding the barrel because the top end face of the barrel or cover is exposed in any case and there is no need to lift a part which has a cylindrical periphery bonded to the concrete or other material of the street covering. As the pilot extension is carried by the cover itself and extends into the barrel body through any attachment which has been interposed, and the barrel body has also ribs which cooperate with the pilot extension, the cover will be reliably held in any case without need for a fixing bolt or the like. It will be understood that the pilot extension of the cover will locate any attachment in position because it extends through the same.

In a development of the invention, each of the conical seat faces of the barrel body, attachments and cover is downwardly adjoined by a cylindrical centering surface, which may be subsequently machined without special expenditure so that the fitting of the mating parts will be further improved.

Old valve access barrels having a cylindrical or prismatic seat for the cover are often still installed in streets. To enable a modification of such barrels or to increase them in height according to the teachings of the invention, a usual barrel body having a cylindrical or prismatic seat for the cover is provided with a transitional attachment, which fits said seat and forms a conical seat face and an adjoining centering surface for the cover and any remaining attachment and carries a hollow cylindrical guide, which depends into the barrel body and serves to guide the pilot extension of the cover. Said guide may be divided into segments.

Several embodiments of the invention are shown by way of example on the drawing, in which:

FIGS. 1 and 2, respectively, are a vertical axial sectional view and a horizontal transverse sectional view taken on line Il-II of FIG. 1 and show a built-in valve access barrel.

FIG. 3 is an axial sectional view showing a valve access barrel with two attachments before theparts are assembled.

FIGS. 4 and 5 are top plan views showing two different covers. I

FIG. 6 is an axial sectional view showing the top portion of a valve access assembly provided with a cover.

FIG. 7 is a bottom view showing the cover of FIG. 6.

FIG. 8 is an axial sectional view showing an old valve access barrel provided with a transitional attachment.

The valve access barrel comprises a frustoconical, hollow barrel body 1, which has a bottom flange 2 and an open bottom and is closed at its top by a cover 3. The barrel body is provided with conical seat faces 4 for engaging the cover; these seat faces are downwardly adjoined by cylindrical centering surfaces 5. The cover 3 carriers a hollow cylindrical pilot extension 6, which extends into the barrel body and cooperates with three longitudinally extending, radial ribs 7 formed in the barrel body. The pilot extension may be formed with longitudinal slots dividing it into segments. The cover is formed with an undercut central bore 8, at which the cover can be engaged and lifted. The bore 8 has two diametral slots 9, which extend to the periphery of the undercut portion I0 (FIG. 4) so that a wrench which is provided at its end with a crosspin or which is formed like a hammer head can be inserted and then turned to interlock with the cover 3. FIG. 5 shows a modification in which the bore 8a is oval and flares downwardly to form the cylindrical undercut portion 10.

As is shown in FIG. 3, the height of the barrel may be changed and adjusted to a desired street level by the use of annular attachments 11, 11a of different height on the barrel body 1. These attachments ll, Ila have conical seat faces 4 and cylindrical centering surfaces 5 like those of the cover 3 and the barrel body I so that the cover 3 can be inserted into any of the attachments ll, Ila just as into the barrel body I. The attachments are provided at their periphery with protruding noses 12, by which the attachments are anchored in the surrounding street covering against rotation.

In the embodiment shown in FIGS. 6 and 7, the pilot extension of the cover 3 is formed by three longitudinally extending, radial ribs 611, which bear on transverse ribs 7a of the barrel body 1.

According to FIG. 8, the barrel bodly la has a conventional, cylindrical seat 13 for engaging the cover. The existing cover is hinged to an eccentric pin, which extends through the bore I4 and is capable of a limited axial displacement so that the cover can be lifted out and pivotally moved to the side. To alter such an old barrel in accordance with the teachings of the invention, the existing cover and its mounting pin are removed. A mating transitional attachment I5 is inserted into the seat 13 for the cover and is formed with the conical seat face 4 and the adjoining centering surface 5 for a new cover or the attachments. The transitional attachment I5 carries a hollow cylindrical guide 16, which depends into the barrel body la iand is divided into individual segments. The guide 16 serves to guide the pilot extension of the cover. In this case, the pilot extension of the cover must also be longitudinally slotted so as to accommodate the portion which is formed with the bore 14. Hence, the transitional attachment l5 enables an increase of the height of old valve access barrels and a provision thereof with the cover according to the invention.

Iclaim:

l. A valve access barrel for use in streets, which comprises a barrel body structure having a bottom flange and open top and bottom ends, a cover detachably connected to and closing said top end thereof, and a pilot extension carried by said cover and depending into said barrel body structure and engaging the same, said cover having a largest outside diameter which is smaller than the outside diameter of said barrel body structure at said top end thereof and being formed with a downwardly facing, conical seat face, said barrel body structure being formed with an upwardly facing, conical seat face in mating engagement with said seat face of said cover, and comprising an annular attachment structure which is formed with said open top end of said barrel body structure and said upwardly PATENIEUFEB 9m 3,561,471 SHEET 2 OF 3 Asu D. Sands ATTORNEY INVEN TOR PATENTEUFEB elem 3 55 47 SHEET 3 UF 3 INVENTOR Asa D. Sands ATTORNEY SAFETY VALVE RELATED APPLICATION This application is a continuationin-part of my copending application Ser. No. 637,7]4, filed May II, 1967 now abandoned.

This invention is an improvement over the inventions covered in my Pat. Nos; 2,623,725, granted Dec. 30, 1952; 3,085,589, granted Apr. 16, 1963; 3,106,937, granted Oct. 15, 1963; and 3,122,162, granted Feb. 25, I964.

This invention relates to an improved safety valve for fluid conduits incident to operation of fluid actuated tools, distribution of gas for welding, distribution of gas for heating and chemical uses and the like, which will prevent injury to personnel, damage to equipment and loss of fluids in case of accident. l

A purpose of the invention is to provide a safety valve which is substantially free of valve flutter resulting from an unequal distribution of fluid flow around the valve member.

It is an object of the invention to provide a stream lined valve member which is centrally located in a valve chamber and which will cause fluid to divide and flow equally around the circumference of the valve member.

It is another object of the invention to provide a safety valve which is spring supported and spring biased to an intermediate position within a valve chamber between opposed valve seats and which is caused to move axially relative to one of the valve seats as a result of an even distribution of fluid flow around the circumference of the valve member when a pressure dif ferential across the valve occurs.

These and other objects, advantages and novel features will be apparent from the following description and the accom panying drawing.

In the drawing:

FIG. 1 is an axial sectional view of the valve of the invention.

FIG. 2 is a side elevation of the valve of the invention looking from one end.

FIG. 3 is a fragmentary axial sectional view of the valve of the invention seated at the outlet end.

FIG. 4 is an axial sectional view of a modified form of the valve of the invention.

FIG. 5 is a sectional view of the modified valve form taken on line 5-5 of FIG. 4.

FIG. 6 is an axial sectional view showing another modified embodiment of the invention.

FIG. 7 is a crosssectional view, taken substantially in the plane of the line 7-7 in FIG. 6.

FIG. 8 is an axial sectional view of another modified embodiment.

FIG. 9 is an enlarged, fragmentary sectional detail of a valve member equipped with a hollow supporting rod.

FIG. 10 is a fragmentary axial sectional view showing another modification.

FIG. 11 is a cross-sectional view, taken substantially in the plane of the line 11-11 in FIG. 10.

FIG. 12 is an elevational view on an enlarged scale of one of the spiders used in the embodiment of FIGS. 10 and l 1.

FIG. 13 is a fragmentary sectional detail of the spider.

FIG. 14 is an axial sectional view of still another modified embodiment of the valve.

FIG. 15 is a fragmentary enlarged sectional view of the valve member used in the embodiment of FIG. 14.

FIG. 16 is a fragmentary enlarged sectional view of a modified valve member.

FIG. 17 is a fragmentary enlarged sectional view of another modified valve member.

In FIG. 1 l have illustrated one form of my safety valve assembly which is particularly useful in fluid conduits transporting gas where the leakage of the gas would be costly because of its economic value, or dangerous because of its hazardous characteristics to life and to property. The safety valve assembly 10 includes a valve body generally indicated by the letter B which body consists of male and female members 11 and 12 connected together by a threaded joint 13. The valve body B when members 11 and 12 are joined includes a hollow intermediate portion 14 having a cylindrical inner surface 15 and circular opposed inner end walls 16 and 17 encompassing a valve chamber C, and hollow endportions 19 and 20 on opposite sides of said intermediate portion 14. The hollow end portions 19 and 20 have corresponding first cylindrical inner surfaces 21,21 and second cylindrical inner surfaces 22,22 encompassing valve passages or ports 23 and 24. The valve chamber C and the valve passages 23 and 24 have a common axis A-A' and the diameter of the valve chamber C is greater than the diameter of the, valve passages 23 and 24. A pair of opposed conical valve seats 25 and 26 are fonned in the valve body B at opposite endsof the valve chamber C between the end walls 16 and 17 respectively, and the second cylindrical inner surfaces 22 and 22' respectively. The second cylindrical inner surfaces 22 and 22' are of greater diameter than the first cylindrical surfaces 21,21 thereby forming opposite annular recesses 27 and 28 respectively. opening into the valve chamber C. The ends of the recesses 27 and 28 form annular shoulders 29 and 30 separating the first cylindrical inner surfaces 21,21 from the second cylindrical inner surfaces 22,22 respectively.

It will be apparent that the valve passages 23 and 24, the valve seats 25 and 26, and the valve chamber C have transverse cross-sectional symmetry about the common axis A-A'.

A valve V is normally positioned centrally within the valve chamber C and is streamlined and symmetrical about the axis A,A' so that fluttering of the valve is avoided. As shown the valve V includes an intermediate disc portion 31, cylindrical land portions 32 and 33 extending from opposite ends 34 and 35 respectively of the disc portion 31, and pointed conical ends 36 and 37 on the cylindrical portions 32 and 33 respectively. The cylindrical portions 32 and. 33 are of a diameter substantially equal to the diameter of the first inner walls 21,21 respectively and fit snugly therein.

A pair of cylindrical helical springs 38 and 39 are seated in the recesses 27 and 28 respectively. The spring 38 has its one end abutting the annular shoulder 29 and its other end snugly encompassing the cylindrical portion 32 of valve V and abutting the valve disc portion end face 34. The spring 39 likewise has its one end abutting the annular shoulder 29 and its other end snugly encompassing the cylindrical portion 32 of valve V and abutting the valve disc portion end face 35. The springs 38 and 39 are of substantially equal strength and normally bias the valve V to a position intermediate the valve seats 25 and 26. The springs 38 and 39 further provide the sole means for supporting the valve V in coaxial relationship within the valve chamber C.

As shown in this embodiment the disc portion 31 of the valve V is of only slightly greater diameter than the cylindrical portions 32 and 33, being far removed from the axis A,A', and is of a slightly less diameter than the diameter of the inner cylindrical surface 15 encompassing the valve chamber C so that an annular space is provided between the inner cylindrical surface 15 and the peripheral surface of the disc portion 31 which has a transverse cross-sectional area substantially equal to the transverse cross-sectional area of the valve passages 23 and 24. The space thus provided normally permits smooth and unrestricted flow of fluid around the valve V through the valve chamber C. v

The disc portion 31 is provided with tapered annular valve faces 40,41 on opposite circumferential edges thereof to provide a snug fit. The valve face 40 is substantially parallel to the valve seat 25 and to the face of the conical end 36. The valve face 41 is substantially parallel to the valve seat 26 and to the face of the conical end 37.

Bypass passages 44 and 45 are provided in the valve body members 11 and 12 respectively. The bypass passage 44 has an opening into the valve chamber C at one end and into the valve passage 23 at the other end and is controlled by a manually actuated, screw threaded bypass valve 46 threaded into bore 48 within the body member 11. The bypass passage 45 likewise has an opening into the valve chamber C at one end and into the valve passage 24 at the other end and is controlled by a manually actuated, screw threaded bypass valve 47 threaded into bore 49 within the body member 12. O-Rings 50 and 51 provide fluid seals between the bypass valves 46 and 47 respectively and their bores 48 and 49 respectively.

The valve V will preferably be made of rubber or of a synthetic rubberlike material which is not susceptible to excessive corrosive action by the fluid being carried through the safety valve. If the fluid being transported is air or other material which can be allowed to seep into the atmosphere without danger the valve C could be made of metal since, it would not then be so important to provide a complete seal between the valve faces 40,41 and the valve seats 25,26.

As previously pointed out the valve member V is symmetrical in form about the axis A,A' and on both sides of a transverse axis passing through the center of the disc portion 31. The angle of inclination of the valve faces 40 and 41 and of the conical ends of the valve V withreference to the longitudinal axis A,A' is shown as approximately 45 but may be a few degrees greater or less. As shown this slope extends from the tips of the conical ends of the valve to the flat top of the disc portion 31 and includes the tapered valve faces 40 and 41, being broken only by the flat cylindrical portions of lands 32 and 33 over which the ends of the springs 38 and 39 are fitted. By reason of this construction not only is a tight seal insured when the valve is seated in either direction, but a streamlined construction is provided in either direction whereby the fluid passing through the valve is caused to divide and flow smoothly and equally around the circumference of the valve member, thus avoiding undesirable valve flutter. Moreover, since the cylindrical shoulders or lands 32 and 33 are of only slightly less diameter than the disc portion 31 the springs alone will be enabled to support the valve without the assistance of any other means more readily than would be the case if the shoulders were located nearer the axis A,A', in which case undesirable wobbling of the valve would be likely to occur unless additional supporting means were provided. The symmetrical shoulders or lands 32 and 33 are preferably substantially more than one-half way from the axis A,A' to the flat ring or disc portion 31 of the valve in the construction shown in FIGS. 1- --ltl. In the construction shown in FIGS. l417, to be hereinafter described, the lands are of smaller diameter since the spring does not provide the sole support for the valve.

FIG. 3 shows the valve member V with the valve face 41 snugly seated against the right-hand valve seat 26 completely shutting off the flow of fluid from the valve passage 23 into the valve passage 24. Above atmospheric pressure in the valve conduit 23 will keep the valve V seated in the position shown in FIG. 3 as long as the pressure in passage 24 is atmospheric.

FIGS. 4 and 5 illustrate a modified form of the invention which is designed for use in an air line, or other fluid line where the fluid can be permitted to escape into the atmosphere in small amounts. Instead of providing bypass passages in the valve housing as in the embodiment shown in FIGS. 1-3, a central passage 52 is provided along the longitudinal axis of the valve V. The passage 52 is preferably a small diameter, cylindrical bore coaxial with the valve V. The pamage 52 will allow leakage of a small amount of fluid through the valve when the valve has been forced against one of its seats as a result of a differential pressure across the valve as would be the case when a break occurs in the flow line downstream from the safety valve.

In operation thev safety valve assembly shown in FIGS. 1 to 3, when used to shut off the flow of gas in a gas line'in the event of a break is positioned in a gas line between a pressurized gas source and a utility device. Normally the valve member V is positioned midway between the valve seats 25 and 26 but should a break occur in the downstream side of the flow line from the safety valve, a pressure differential will develop across the valve V, which will force the valve V against the downstream valve seat. As shown in FIG. 3 the low pressure occurs in passage 24 and the high pressure occurs in passage 23. The valve V will remain in the position shown until the break in the downstream flow line is fixed and pressure is again built up in the valve passage 24 to equal the pressure in the passage 23.

The bypasses 44 and 45 are provided with manually controlled valves 46 and 47 so that an operator can selectively open one of the normally closed bypass valves 46 or 47 to permit fluid from the valve chamber C to flow around the closed valve V and build up pressure in the low pressure valve passage. Valve 47 would be opened in FIG. 3 to pennit fluid to flow into passage 24 until the pressure across valve V is equalized and the valve V is returned to its normal open position by means of the springs 38 and 39. Once the valve V has been returned to its normal open position the operator again closes the bypass valves 46 and 47 so that gas would not escape through the bypass passages into the atmosphere if another break should occur in the flow line.

The valve V shown in FIG. 4 is normally positioned as shown and would be forced to seat against its valve seats located on the downstream side should a break in. the downstream flow line occur. The main volume of fluid flow would be shut off by the valve V but a small amount of fluid would still flow through the central passage 52 into the downstream passage. However as long as the break in the downstream flow line remains open no pressure can build up in v the downstream valve passage. When the break in the downstream flow line has been repaired, the fluid flowing through the central passage 52 will build up pressure on the downstream side of the valve V until the pressure across the valve V is equalized, at which time the valve V will be returned to its normally open position by the springs 38 and The stream lined valve V supported solely by the springs 38 and 39 is substantially flutter free because of its symmetrical slope with respect to its axis and because of its position on the common axis of the valve chamber C. The surface area of the valve V facing the path of fluid flow is uniformly distributed about the valve axis AA' so that the'axial pressure of fluid on the valve is also uniformly distributed with respect to the valve axis. There are therefore no unequal forces tending to cant the valve V relative to its axis, and the valve will move axially into sealing engagement with one if its seats 25 or 26 when a differential pressure occurs across the valve.

The valve assembly 10 can be made more cheaply than valves of a similar type requiring guide stems and guide bearings.

Because my valve is substantially flutter free and will be caused to seat properly as a result of a differential fluid pressure across it, the operation of my improved safety valve is fully as satisfactory as valves provided with guide stems and guide bearings and even more so because frictional contact between the valve stems and guide bearings are eliminated.

The parallel conicalfaces 36 and 37 of my valve V and the valve faces 40 and 41 on the same side of the valve are features of my valve which help to eliminate turbulence within the valve chamber and help to cause a uniform distribution of fluid flow around the circumference of the valve.

Reference is now drawn to another modified embodiment of the valve shown in FIGS. 6 and 7. For most part this embodiment is the same as that in FIGS. 1-3, so corresponding reference numerals are used to identify the corresponding parts. However, this embodiment is characterized in that additional means are provided to assist the springs 38, 39 in supporting the valve member V in the chamber C. These means involve providing the outer ends of the springs 38, 39, that is, the ends thereof which-project into the valve port recesses 27, 28, with integral extensions 60, the latter being directed radially inwardly and terminating in eyes or bearings 61 located on the longitudinal axis of the valve, as is best shown in FIGS. 7. The eyes 61 provide bearing which slidably receive the end portions of a rod 62 which extends axially through and is secured in the valve member V. Thus, the bearings 61 coacting with the slidable rod 62, effectively guide the movement of the valve member toward and away from the valve seats and assist the springs 38, 39 in properly supporting the valve member in the chamber C. When the valve is closed, fluid may be bypassed through the bypass means 46, 47-, as in the embodiment of FIGS. 1-3.

The modified embodiment of, FIGS. 8 and 9 also provides the additional supporting meansfor, the valve member as in FIGS. 6 and 7, but in theenvironment of the valve of FIGS. 4 and 5 where the fluid bypass is made throughthe center of the valve memberitselfl Thus, in the embodiment of FIGS. 8 and 9, the valve member supporting rod 620 is hollow so as to provide anopen ended axial passage 63 therethrough, as shown in FIG. 9. This passage establishes communication between the valve ports 23, 24 when the valve member is in either of its closed positions.

In another modified embodiment shown in FIGS. 10-13,-

the valve member V is also provided with a supporting rod which may be either the solid rod 62 or the hollow'rod 624, depending upon whether the fluid bypass is made through the valve body as in FIG. 6 or through the valve member as in FIG. 8. In either event, in theembodiment of FIGS. 10-13 the end portions of the rod 62 (or 62a)'a re slidably joumaled in a pair of spiders 64 which are seated in the valve port recesses 27, 28

in abutment with the shoulders 29, 30. i

As is bestsown in FIGS. 12 and 13, each of the spiders 64 comprises a central, tubular bearing portion 65 and a set .of radially outwardly extending arms 66. The bearing portion 65 slidably accommodates the valve member rod 62 (or 62a), while the outer end portions 67 of the arms 66 are in abutment with the valve port shoulders 29, 30. These end portions of the tioned spring seating lands- 80. For sealingly engaging the valve seats 75, 76, the valve member body 89 is also provided with chamfered peripheral edges 90 and with apair of sealing rings 91 of Neoprene, or the like. The rings 91 are seated in annular grooves 92 formed in the periphery of the body 89, the grooves being separated by an intermediate land portion 9 r If the valve is a gas valve, a modified valve member shown in FIG. 16 may be used. The body 89a of this valve member is I provided with only one chamfered edge 90 and only one seal ing ring 91 for coaction only with the valve seat 76 on the downstream side of the valve. Otherwise the arrangement is the same as already explained in connection with FIG. 14.

Finally, if the valve is used only for transmission of air, the valve member of FIG. 17 may be utilized, this being simply in the fonn of a, disc body 89b having a rounded periphery 94 for engaging either of the seats 75, 76. In such event the sealing rings 91 are omitted and the fluid bypass 8488 through the arms are provided with notches 68 for seating the ends of the springs 38, 39 it being understood that in this embodiment the ends of the springs are not equipped with the bearing forming extensions 60, 61, as in the embodiments of FIGS. 6-8.

FIGS. 14 and 15 illustrate another modified embodiment of the valve of the invention, wherein thevalve 'body B consists.

of a pair of complemental sections 70, 71 which are screwthreadedly connected together as at,72'. The valve body defines a valve chamber C with coaxialvalve ports 73, 74 having valve seats 75, 76 facing the valve chamber. The valve ports are equipped with annular shoulders 77, 78 for abutment by outer ends of tapered, helical springs 79 located at the opposite sides of the valve member V, the valve member being.

equipped at its opposite sides with circular lands80 on which the inner ends of the springs are seated.

To assist the springs 79 in supporting the valve member V in the chamber C, the valve member is provided with an axial rod 81, the end portions of which are slidable in bearings 82 provided on extensions 83 of the outer ends of the springs 79, as already described in connection with FIGS. 6-9. t

The valve member supporting rod. 81 is solid, and when the valve member engages the valve port seat 76, fluid may be bypassed from the chamber C to the valve port 74. through bypass ducts 84, 85 which are formed in the body section 71 in communication with a bore 86 with which the section 71 is also provided. As will 'be noted, the'duct 84 opens into the chamber C, while the duct 85 opens into the valve port 74. A bypass valve plug 87, equipped with suitable sealing rings 88,

is screw-threaded into the bore 86, so as to control the flow of fluid through the bypass ducts.

The arrangement is particularly well suited for use in an explosion valve, in which the valve member V comprises a disclike body 89 provided at its opposite sides with the aforemenbody section 71 alsoneed not be provided, since the valve member supporting rod 810 may be hollow to provide a fluid bypass therethrough, as already mentioned in connection with FIGS. 8 and-9.

Although the embodiment of FIG. 14, using a valve member in accordance with FIGS. l5, 16 or 17, has been shown as having the valve member rod 81 (or 81a) slidably joumaled in the bearings 82' carried by extensions 83 of the springs, 79, it is to be understood that, alternatively, the rod of the valve member may be joumaled in spiders seated in the valve ports 73, 74 against the shoulders 77, 78, as in the embodiment of FIGS. 10-13.

I claim:

1. In a safety valve, the combination of a valve body defining a valve chamber having a longitudinal axis with valve ports at opposite ends of said axis, annular shoulders in said valve ports,and'a valve seat on at least one of said ports facing said chamber, a valve member of a smaller cross section than said chamber disposed in the chamber and movable axially toward and away from said valve seat for sealing engagement with and disengagement from the latter, said valve member'including an intermediate disclike portion and a pair of diametrically reduced lands at opposite sides of said intermediate portion, and means for supporting said valvemember in said chamber in a normally axially spaced relation from said seat, said supporting means comprising a pair of coil springs disposed at opposite sides of said valve member, said springs having adjacent inner ends seated on the respective lands in abutment with said intermediate portion of the valve member and having outer ends extending into the respective ports for abutment with said annular shoulders together with a rod secured in and extending axially through said valve member with end portions of the rod projecting into said ports, and bearing means provided in said ports, said bearing means having the end portions of said rod slidably joumaled therein, whereby to assist outer ends of said springs.

2. The valve as defined in claim 1 wherein said extensions terminate in coaxial eyes which constitute said bearing means for the end portions of said rod.

3. The valve as defined in claim 1 wherein said rod is hollow and provides a bypass means providing restricted communica- 1,. 

1. In a safety valve, the combination of a valve body defining a valve chamber having a longitudinal axis with valve ports at opposite ends of said axis, annular shoulders in said valve ports, and a valve seat on at least one of said ports facing said chamber, a valve member of a smaller cross section than said chamber disposed in the chamber and movable axially toward and away from said valve seat for sealing engagement with and disengagement from the latter, said valve member including an intermediate disclike portion and a pair of diametrically reduced lands at opposite sides of said intermediate portion, and means for supporting said valve member in said chamber in a normally axially spaced relation from said seat, said supporting means comprising a pair of coil springs disposed at opposite sides of said valve member, said springs having adjacent inner ends seated on the respective lands in abutment with said intermediate portion of the valve member and having outer ends extending into the respective ports for abutment with said annular shoulders together with a rod secured in and extending axially through said valve member with end portions of the rod projecting into said ports, and bearing means provided in said ports, said bearing means having the end portions of said rod slidably journaled therein, whereby to assist in supporting said valve member in said chamber, said bearing means comprising integral radially inward extensions of the outer ends of said springs.
 2. The valve as defined in claim 1 wherein said extensions terminate in coaxial eyes which constitute said bearing means for the end portions of said rod.
 3. The valve as defined in claim 1 wherein said rod is hollow and provides a bypass means providing restricted communication between the low pressure side and the high pressure side of the valve when the valve member engages its seat as the result of pressure differential across the valve. 